Practice your craft. In a competitive field such as music, you can't afford to miss notes. The greatest musicians make playing look effortless, but their genius is actually the result of hours spent playing the same exercises over and over again. Ideally, you should set aside four to six hours a day to practice.
Think about what makes you unique as a musician. Do you write your own songs? Do you play an unusual instrument, or could you learn one? Whatever it is, use that as a marketing gimmick.
Market yourself. These days, it's not enough to just have a website or a pile of flyers --- you need to be on social media sites and professional networking sites, too. Many musicians keep blogs. If your practice schedule doesn't allow you time to maintain a robust online presence, hire or bargain for someone to market you.
Make a demo CD. As a musician, a demo is as valuable as your resume. Don't expect to get noticed without one.
FIlm a music video. Any musician can make a decent quality video with some friends, a cheap camera and some editing software. The benefit of having a music video on your site will far outweigh the cost.
Cultivate an individual style. If you play punk music, don't dress like all the other punk kids out there, as tempting as it may be. Cultivate a style that will make your audience want to know more about you.